You steal away a creature's ability to rest or sleep. The target of this spell cannot sleep, accruing penalties for fatigue in addition to being unable to heal naturally. Even creatures such as elves that normally do not sleep are unable to get a proper rest with which to re-energize to gain spells or heal naturally. This spell can be countered by a sleep spell and it can be used to counter a sleep spell or other magical means of inducing sleep.

Editor's Note: This spell mentions that elves do not require sleep. This is likely a hold-over from earlier versions of the game. The Pathfinder system eliminated this benefit to elves.